The effect of ethanol, methanol, acetone and water extracts of leaves of 11 plant species, used in the folk medicine, against six antibiotic resistant clinical pathogens was evaluated by the agar-well diffusion method. The obtained results indicate that most of the extracts revealed antimicrobial activity. The water extract of A. discoridis leaves exerted significant effect and recorded the lowest MIC and MMC. Ethanol leaf extraction method is the best. It produced broad-spectrum of antimicrobial activity followed by methanol leaf extraction. Interestingly, methanol extraction method was found to be the most effective extraction method of anticandidal agents. Among the pathogenic bacteria tested, S. pneumonia was the least sensitive. Nevertheless, the anticandidal MIC and MMC values are higher than antibacterial values suggesting that C. albicans is less sensitive to plant leaf extracts. In conclusion, aqueous extracts of A. discoridis leaves exhibited the highest potency against all pathogens tested. Thus, this study confirms the efficacy of some plant extracts as natural antimicrobials and suggests the possibility of employing them in drugs for treatment of infectious diseases caused by the test pathogens.
Maher Obeidat, Mohamad Shatnawi, Mohammad Al-alawi, Enas Al-Zu`bi, Hanee Al-Dmoor, Maisa Al-Qudah, Jafar El-Qudah and Ismael Otri, 2012. Antimicrobial Activity of Crude Extracts of Some Plant Leaves. Research Journal of Microbiology, 7: 59-67.